Self-contained abrasive applicator



March 4, 1958 w. F. TILDEN SELF-CONTAINED ABRASIVE APPLICATOR Filed Jan.10. 1956 I /2 \\N xx 1 m w a5. Y 8 W 9 e M I23- d/ 7- MT k 0 7 "H 9 w wn. w M 3 M 1 A N 4. 3 9 L J 8 a z 7 r M a 6 58 M A W v Y. 4 B

United States Patent SELF-CON TAINED ABRASIV E APPLICATOR William F.Tilden,San Francisco, Calif.

Application January 10, 1956, Serial No. 558,212

lo Clainis'. (CI. 32-58) The present inventionconstitutes anadvance overthe abrasive applicator which. is disclosed and claimed in my co-pendingapplication, SerialNo. 521,029, filed July 11, 1955, and entitledAbrasive Applicator. This application is. a continuation-in-part of theaforesaid co-pending application.

A primary object of my improvement is to provide a self-containedabrasive applicator possessing unique and more positive control'of thevolume of abrasive emitted. from the applicator.

Another important object of the invention is to provide an applicator ofthe indicated nature which is additionally characterized by uniquefeatures to prevent packing of the abrasive in the. hopper therebyinsuring free flow thereof to the delivery nozzle. 7 I

A still further object of my present inventionis to provide aself-contained abrasive applicator of'the aforementioned character whichaffords more facile replenishing of abrasive.

Other objects ofthe invention, together with some off the advantageousfeatures thereof, will. appear from the following description of apreferred embodiment .of'the present improvementwhich is illustrated inthe accompanying drawings. It is to be understood, however, that I amnot to be limited to the preciseembodiment illustrated, nor totheprecise arrangement of the various parts thereof, as my invention, asdefined in the appended claims, can be embodied in a plurality andvariety of forms.

Referring to the drawings:

Fig. 1 is a longitudinal sectional view of a preferred embodimentoftheimprovement, some parts beingshown in fragmentaryv illustration forlack of space and one part being shown in elevation.

' i Fig. 2 is, an enlarged detail, partly in section, of the elements atthe gas inlet end of the. hopper and.their association with'the gasdryer.

Fig. 3 is an enlargedsectional detail of elements surroundingtheabrasive carryingrigid tube to prevent return of, gas within the hopper.

In itspreferred form, the self-contained abrasive applicator of. mypresent, improvement preferably comprises a hopper forholdingavolume ofa dental abrasive, a .pistonwithin saidhopper for maintaining adiminishing volume. of abrasive in said hopper under pressure; saidhopper havingjan air ,inlet atoneendlthereof, an abrasive carryingrigidtube supported'in said hopper. in. axial align-. ment with.said'air inlet; said rigid tube having an annu-- lariporttherein'adjacent to said air inlet'end of'saidlhopper, a hollo l t Valveprojectinginto said tube and controlling said port; said valveregulating the quantity of abrasive,entering said'tube from said hopperthrough said port, meansior-causinga flow. of a stream ofdry air throughsaid hollow jet valve and said rigid tube to effect the withdrawal ofabrasive-fromsaid hopper and entrainment thereof in said air stream,together with a hollow hand-pieca a rigid tubing" supported in isaidhand-piece, a. flexible conduitiestablishing communication betweensaid rigid-tube and" said rigid tubing, a nozzle 'on" said hand-piece incommunication with said rigid tubing, and manually operable means forcontrolling the volume of abrasive-laden air emitted from said nozzle.

The principal elements of the present improvement, as illustrated inFig. l of the annexed drawings, comprise'a handpiece'6, a hopper 7 forholding a volume of a powdered abrasive 8, means for supplying a gasunder pressure, such as an air compressor not shown, a .gas dryingapparatus 9, together with a plurality of elements hereinafter describedfor efiecting the emission of a controlled volume of abrasive-laden gasat desired locations, such as various teeth to be cleaned or ground forfilling operations or other dental work.

As illustrated in Fig.1, the hand-piece 6 of my improved self-containedabrasive applicator. preferably comprises a rigid hollow elongated body11, preferably fabricated from a light-weight metal or from a plasticmaterial, which is closed at its inlet end by a removable apertured cap12'and which is conveniently knurled, as at 13', on its outer surfacefor ready handling. At itsopposite or outlet end, the body 11.isprovided withv a removable closure 14 having an end opening 16 thereinfor the passage of a nozzle holder 17 which carries at its outer end anozzle tip 18;'the closure member 14 defining an interior chamberbetween the adjacent end 19 of the body. and the closure whichconveniently is filled with felt packing 21'. The nozzle holder. 17isported, asat 22, to permit the escape of'a small volume of filteredgas free of abrasive, which isvented through the felt packing 21 i tothe atmosphere through opening 16 in the closure 14 thus aiding in thecontrol.of.the flow of abrasive-laden gas from the nozzle tip 18 of thehand-piece. I Thehandpiece jinteriorly supports a rigid'tubing 26 byfittingthe same through, the aperture. of'cap 12 at the, inlet end of:the body and through the bore of a slidable member 27 as well asbyfitting the; same into one end of a short rubber tubing 28. The rubbertubing 28v is extended through apassage 29' formed in a valve body 31-which is in screw-threaded engagement with the rigidbody 11- adjacent tothe nozzle end of the hand-piece. .Nozzle In accordance with the presentinvention, I provide.

means on the hand-piece 6 for pinching therubber tubing 28 to anyextentdesired thereby regulating the volume.

' of abrasive-laden. gas passing therethrough to the nozzle tip 18whichis in communication with tubing 28 through nozzle holder 17. Thesemeans constitute, in eifect, a valve" for opening and closing tubing 28and comprise apinching element or. depresser 32, preferably formedfto anangle-shape as shown, which is disposed in a.transverse bore 33 ofvalvebody Stand which is inbearing engagement with a cam surface. 34' on thestemI36- of a finger-button 37;. The. button 37 is-slidably mountedon'the hand-piece 6 bymeansof a rod 38. which is.

engaged by a' screw39 'extending'through the button 37 sothat flowtherethrough is' completely shut oif. closed position of the valve, thefinger-button 37 rests in its extreme position adjacent to the nozzleend of the handpiece. To open the valve thebutton 37 is moved toward therear of the hand-piece and the slidable movement of the'button 37 isindicated by the double-arrow line 40..

The rearward'movement of finger-button 37 effects the rearward movementof the slidable member 27, through the'medium'of-"theconnectedrod38,againstthe action of a spring 41 which is confined within the body 11between the cap 12 thereof and the slidable member 27 and which iscompressed by the rearward movement of thebutton 37., Release of thefinger from finger-button 37 effects a complete closing of the valve, orcomplete pinching of the flexible tubing 28, as shown in Fig. 1, by theaction of spring .41 which moves slidable member 27 and rod 38, togetherwith connected button 37, to their extreme positions to the left oradjacent to the nozzle end of the hand-piece 6. I thus have provided apositive control of flow of abrasiveladen gas to the nozzle tip 18.

A supply of a powdered dental abrasive 8 is maintained in the hopper 7which preferably is formed with a body portion of cylindricalconfiguration the walls of which converge at one end to provide arelatively narrow neck 51 defining a relatively narrow passage, thewalls of the passage being threaded, as at52, for threadedly receivingsupporting elements for a jet nozzle hereinafter described. At theopposite end, the hopper is closed by a removable closure 54 which isseated, with an interposed rubber washer 56, on the rimof the hopperpreferably by means of a bayonet clutch connection; the closure 54 beingformed with an integral elongated hollow section 57, projecting normalthereto and centrally of closure 54 and a disc 63 which is removablymounted on the piston 59 by threaded engagement therewith and locked inposition by means of a lock-nut 64; the disc 63 carrying an integralboss 66 about which the coil spring 61 11s coiled. The boss 66 of disc63 is formed with a central bore 67 and serves as a guide and partialsupport for a rigid conduit 68 which extends through the hopper 7,through the bore 67 of boss 66 as well as through the hollow section 57of closure ,54 to project through and beynd such section 57 into thehollow nipple 58 thereof; the conduit 68 terminating short of the neck51 of the hopper and being provided at this end with an enlarged rscction 69 in which a transverse port 71 is formed for permittingpassage of the abrasive powder 8 into the conduit.

A source of gas under pressure, such as an air compressor, not shown, isprovided for delivering a stream of an under pressure to and through therigid conduit 68. Since air delivered from an air compressor usually hasconsiderable moisture therein, I preferably pass the air delivered fromthe compressor through a drying chamher which conveniently is defined bya housing 73 contaming a quantity of a dehydration substance 74, such asSilica Gel or the like, which effects the removal of substantially allmoisture from the air passing through the chamber. The housing 73 isclosed at one end and is provided with a removable cover 76 at itsopposite end; the cover 76 preferably being formed with a short passage77 therein which is enlarged at its inlet end to receive the nipple 78of a flexible conduit 79 leading from the air compressor, not shown.Secured'to the bottom of the cover 76 of housing 73 and suspendedtherefrom within the chamber 74 is a narrow tube 81 which communicateswith the air compressor throughthe inlet passage 77 in the cover 76. Thecover 76 of housing 73 is formed with an integral annular boss'82 whichis internally threaded for efiecting threaded engagement with the neck51 of hopper 7, the neck 51 being exteriorly threaded for i an inclinedthreaded passage 92 into which a screw 93 is jet nozzle 86 for causingan air stream to flow under pressure through the rigid tube 68 of thehopper 7; the jet nozzle, in effect, serving as a needle valve forcontrolling the quantity of abrasive 8 that is withdrawn or aspiratedfrom the hopper through port 71 for entrainment in the air stream movingthrough tube 68. The jet nozzle 86 is of sufficient length to projectthrough the cover 76 of the housing 73 and into the compartment orchamber 74 thereof in order to pick up air delivered from the aircompressor, not shown, through flexible hose 79 to the air chamberthrough the rigid tube 81 supported therein, As shown, the jet nozzle 86conveniently is supported in operative positionbymeans ofan exteriorlythreaded sleeve 87 and a threaded bushing 88 in which the jet nozzle issnugly fitted and held; the sleeve 87 and bushing 88 being threadedlyconnected into the neck 51 of the hopper 7 through the medium ofinternal threads 52 of the neck 51. As shown in the enlarged view ofFig. 2, the bushing 88 is recessed for receiving an O ring 89 and alongitudinally threaded bore is formed in the bushing for receiving alocking screw 91 which, upon being tightened, locks the bushing tightlyabout the jet nozzle and against the sleeve 87 to firmly hold the jetnozzle against displacement. The neck 51 of the hopper 7 is formed withloosely threaded; such passage 92 serving as a vent to the atmospherefora small amount of air or gas that escapes from the rigid tube 68 throughport 71 during the operation of the compressor. The sleeve 87 is formedwith an inner annular flange 94 thereon which isin abut ting engagementnormally .with the bottom of the hopper 7 to preventthe dropping of thesleeve through the air inlet end of the hopper, and a felt washer 96 isinterposed between the fiange94 of the sleeve and the bottom of thehopper to filter out any abrasive powder tending to pass out through thevent 92 in the neck 51 of the hopper., By this arrangement of theabove-described parts, jet nozzle 86 is always maintained co-axial withthe rigid tube 68 of the hopper in order that even flow ofabrasive-laden gas is attained. As illustrated, the tapered end of jetnozzle 86 defines. a relatively narrow orifice 97 which at all times isdisposed'within the enlarged section 69 of the rigid tube 68 of thehopper despite the relative position of the orifice of the jet nozzlewith respect to the port 71 of tube 68. With the aircompressor inoperation, a venturi action occurs within the enlarged section 69 of thetube 68 and in all open positions of the jet nozzle or needle valve 86 aquantity, ofthe powdered abrasive 8 will be aspirated and withdrawn fromthe hopper for entrainment in the air stream flowing through the jetnozzle and associated tube 68. Adjustment of the needle valve or jetnozzle 86 with respect to the port 71 of the tube 68 is effected byslight turning of the hopper 7 with respect to the housing 73.

In order that pressures be equalized on each side of the piston 59 asthe quantity of the powdered abrasive in the hopper 7 is graduallydiminished, and to permit the piston to move freely under the influenceof the spring 61 and not be adversely afiected by differences in airpressures, I 6

preferably provide a small bleeder port 98 in the tube 68 adjacent toits outlet end which allows the continuous escape of a small quantity ofair between the sleeve 62 and the inner wall of the section 57 of thecover 54 of the hopper to fill the space in the hopper in back of thepiston 59. The powdered abrasive in the escaping material from thebleeder port 98 is filtered out through a felt packing 99 which isdisposed within a cup-like enlargement 101 of the sleeve 62 adjacent tothe bleeder port 98. A suitable annular .bushing 102, recessed toreceive an O ring 103, serves as a backing for the felt packing 99; thebushing being screw-threaded into position onthe bottom of the cup 101and the O ring 103 serving to seal the joint against leakage of air orabrasive.

To complete the assembly, I provide a fiexibleconduit .96 i i dete n telength t es g ma i tion' between the rigid tube26 of the: hand-piece. 6and the rigid tube 68 of the hopper; one end of the conduit; 106 beingattached to the projecting end of the rigidtube 26 of the hand-piece andthe other end of the conduit 106 being connectedto the projectingnipple,58 of the hopper cover. With the flexible tubing 28 of the hand-piece 6closed and with the air compressor in operation, a head ofabrasive-laden gas is always available". for delivery, to the nozzle tip18 and controlled amountsof the abrasiveladen gas will be emitted fromthe nozzle by manipulation or" the finger-piece 37 of the hand-piece.

The applicator of my present improvement is entirely portable and canreadily be set up for connection to a small air compressor which isusually available in a dentists otfice. The drying chamber housing 73can be of such a size as readily to fit in the space normally occupiedby a medicine bottle in a conventional dental unit and in which heat issupplied to the bottle. Thus, the drying chamber 74 of my improvedapplicator can be kept warm and the air from the compressor warmed as itpasses through the chamber. This feature is advantageous when treatingsensitive teeth, i. e., sensitive to cold or thermal changes, and thusreduces tendency to pain.

By virtue of the construction of the hopper 7, replenishing of thepowdered abrasive 8 therein is greatly facilitated. All that is requiredto be done, to fill the hopper, is to remove the closure 54 thereof andwithdraw the piston 59 by grasping and pulling on the spring 61 which isanchored to the boss 66 of disc 63 which, in turn, is secured to thepiston; and then pour a new supply of powdered abrasive through the thusopened top of the hopper and thereafter replace the removed parts. Thesleeve 87 with its flanged extremity 94 is always in fixed relation tothe hopper 7 and efiectually seals the hopper through the medium of feltwasher 96 against the escape of abrasive through the passage of the neck51 of the hopper. The spring-urged piston 59, having substantially equalpressure on both sides thereof, follows the diminishing supply ofabrasive in close contact therewith at all' times.

It is to be understood that the appended claims are to be accorded arange of equivalents commensurate in scope with the advance made overthe prior art.

I claim:

1. A self-contained abrasive applicator comprising a tubular hand-piece,a first rigid tube supported in said hand-piece, a flexible tubing insaid hand-piece communicating with said rigid tube, a hopper, a quantityof abrasive powder in said hopper, a second rigid tube extending throughsaid hopper; said second rigid tube including an enlarged section havinga port therein, a jet nozzle coaxially supported within said secondrigid tube; said nozzle including a tapered tip for covering anduncovering the port of said enlarged section of said second rigid tube,a gas drying chamber connected to said hopper for relative rotation;rotation of said hopper relative to said chamber effecting the movementof said port of said second rigid tube with relation to said tapered tipof said jet nozzle, a flexible hose establishing communication betweensaid second rigid tube and said first rigid tube, an applicator nozzlemounted on said hand-piece in communication with said flexible tubing,means for causing a stream of gas under pressure to flow to and throughsaid gas drying chamber to cause a stream of dry gas to flow throughsaid jet nozzle thereby to aspirate a quantity of abrasive powder fromsaid hopper through the port of said second rigid tube and to cause thedelivery of a quantity of abrasive-laden gas to said applicator nozzle,and means movably mounted on said hand-piece for selectively pinchingsaid flexible tubing to regulate the amount of abrasive-laden gas tosaid applicator nozzle.

2. A self-contained abrasive applicator comprising a hand-piece, a rigidtube supported within said handtrained in said stream may be regulated.

hopper, a gasdr-yingchamber rotatably'connected. to; said hopperandthroughwhich a gas under pressureis caused to flow, a rigidconduitsupported in' said hopper; said conduit having a port therein, ajet nozzle coaxially supported within said rigid conduit adjacent to theport therein for. uncovering and coveringsaid port in responsetorotation of said hopper relative to. said gas dryingchamber; said jetnozzle establishing communication between said gas drying chamber andsaidrigid conduit of said hopper, and a flexiblehoseestablishingcommunication between said rigid conduit and said rigid tube of saidhand-piece.

3. In an abrasive applicator, a hopper, a quantity of powdered abrasivein said hopper, a gas drying chamber rotatably connected to said hopperand through which a gas is caused to flow under pressure, a rigid tubesupported in and extending through said hopper; said rigid tubeincluding an enlarged section having a port therein communicating withthe interior of said hopper, and a jet nozzle coaxially supported withinsaid rigid tube adjacent to the port in the enlarged section thereof andextending into said gas drying chamber to establish communicationbetween said chamber and said rigid tube and for conducting a stream ofdry gas to the tip of said nozzle whereby powdered abrasive may beaspirated from said hopper and entrained in said stream; rotation ofsaid hopper relative to said gas drying chamber effecting an adjustmentof said jet nozzle relative to the port in the enlarged section of saidrigid tube whereby the quantity of abrasive aspirated from said hopperand en- 4. In an abrasive applicator as defined in claim 3, including apiston in said hopper, and means urging said piston into engagement witha diminishing supply of abrasive in said hopper.

5. In an abrasive applicator as defined in claim 4; said rigid tubehaving a bleeder port therein adjacent the end thereof opposite to saidenlarged section for equalizing pressures on opposite sides of saidpiston.

6. In an abrasive applicator as defined in claim 5, including a filtersurrounding said port for preventing abrasive passing into said hopperon the spring side of said piston.

7. In an abrasive applicator, a hand-piece, a flexible tubing in saidhand-piece through which an abrasiveladen gas is caused to flow, andmeans for selectively pinching said tubing for controlling flowtherethrough; said means comprising a valve body removably fitted tosaid hand-piece adjacent said flexible tubing, said body having atransverse passage therein, a pinching element in said passage engagingsaid tubing, a valve stem in said body having a cam surface thereonengaging said pinching element; said valve stem being adapted to bemanually shifted within said passage to move said cam surface over saidpinching element to fully close said tubing by pinching the same withsaid pinching element and to open said tubing to any desired extent byrelieving the pinching of said tubing.

8. In an abrasive applicator as defined in claim 7, including means forautomatically returning said valve stem to an initial position with saidflexible tubing fully closed upon release of manual pressure on saidvalve stem.

9. In an abrasive applicator as defined in claim 7, including afinger-button on said valve stem projecting outside of said hand-piece,a slidable member fitted within said hand-piece, a spring confinedbetween an end of said hand-piece and said slidable member for urgingsaid member toward said valve body, a rod extending through said valvebody and said valve stem; said rod engaging said slidable member, andmeans connecting said fingerbutton and said rod whereby manual movementin one direction of said finger-button effects slidable movement of saidmember against the force of said spring and repiece, a hopper, aquantity of powdered abrasive in said lease of said finger-buttoneffects a return of said member 7 and said'rod and said valve stemautomatically to their initial positions in response to the action ofsaid spring.

10. In an abrasive applicator, a hand-piece, a flexible tubing in saidhand-piecethrough which an abrasiveladen gas is caused to flow, a nozzleholder supported on 5 said gas from said port insuring an even How ofabrasiveladen gas through said nozzle holder to a point of application.

References Cited in the file of this patent UNITED STATES PATENTS TyreeOct. 6, 1925 Angell Dec. 8, 1953

